Metabolic Activity of Insulin and Temperature Exposure in the Real World: Challenges for People Living With Diabetes

Heat has substantial implications for people living with diabetes (PwD), their medical devices, and diabetes medications. Climate change, increasing dependence on diabetes management technologies, and persistent global inequities in cold chain access underscore the need for this narrative review. Herein, we focus on the diabetes medication insulin and its stability under the influence of temperature. Keeping insulin cold is essential to maintain its biological activity, ie, its ability to lower blood glucose levels. A cold chain is required for the safe transport of insulin from the manufacturer to the pharmacy, and when transported, stored, and used by PwD. PwD have reported experiencing loss of insulin activity in daily life once it is kept outside the refrigerator for longer periods of time. Little evidence exists on the influence of real-world conditions on the biological activity and clinical efficacy of insulin. We see a need for a holistic evaluation of the actual biological activity of insulin when used, stored, or transported in real life by PwD—also outside recommended storage conditions.